Yeah, not sure why you guys think the 480 is the equivalent of a 1070. It is right now due to a lack of development effort for Nvidia. Out of the five major releases I've seen for Equihash, they've all been tailored for AMD.
There is money to be had in Nvidia, there are definitely a lot of people that invested in the hardware and have it available, myself included. There is no software available to take advantage of it though and the only comparable point people have been using is Ethereum... which is just limited by latency and bus width. Most of the big coins right now are based on Dagger (so memory bus limited), this has lead to a artificial inflation and perception in AMD mining.
Sadly, there is almost no one interested in making a good miner for Nvidia. CUDA or OCL, Nvidia miners just get the scraps left over as a side though, such as SA v5. While Nvidia support is there, it's definitely not the forefront of development efforts right now.
The whole open source vs closed source thing I don't get. Developers should be rewarded for their work, this is coming from a miner. A dev fee not only incentivizes current development, but future development too... instead of just being a side project that someone will throw out when they get bored - it shows too. Take Claymore, he's doing it as a full time job. It's no wonder that he puts a lot of effort into it. While MKB is doing a pretty good job, it's obvious that this isn't his job. He has a different job he goes off to do every day and this is more then likely a hobby.
That's the problem with open source development. It's a hobby. It's not a job, unless you can fund a non-profit that essentially turns this into a job or a CO-OP, such as a community open source miner that has a dev fee people use (which I've suggested multiple times over the years), it's going to stay that way. A lot of miners do this for a JOB as such we need professional software written by people who also are employed doing what we do. Miners can't depend on software from hobbyists. I don't mean that in a bad way, just the priorities are completely different.
For instance, Nvidia miners had absolutely no support when a bleeding edge algo came out. This wasn't supposed to be only a AMD payday, this was also a Nvidia payday. I can't even fucking throw money at someone or somewhere to get something done. I'm not a huge miner, but I have quite a bit invested here. Do you know what sort of predicament that makes for someone who is running a business?
I would happily run a 2.5% dev fee miner if it gets things done. I would've even ran that 15% AMD miner if it gave me the same rates, but it doesn't. I still have to go back to Ethereum. That is unacceptable. I'm not the only one running Nvidia hardware too. There are three big name miners for Equihash right now, Silent Army, Claymore, and Optiminer. They're all competing with eachother... and they're all throwing away Nvidia miners like they don't even fucking matter.
Why? There are quite a few Nvidia miners, they do exist... They're either mining Lbry right now or more then likely Ethereum if they're smart.
The reason there is so much AMD development, is there are a lot more miners with AMD cards. They have historically been best investment mining wise. They were better with Bitcoin and Litecoin, (which are both heavily compute limited), because they supported certain key operations in hardware. AMD tends to have better price/performance anyway, even for gaming. The newer algorithms are memory hard on purpose, to be heavily ASIC resistant, there are ASICs for most non memory hard algorithms. Sure a 1070 has more compute than a 480, but it costs 2X as much, so it is kinda silly to buy for mining, when you can get same/faster speed for half the cost. The 1060 3GB is decent choice for Ethereum, but 470 is still a lot better cost/perf.
If you are a developer, you are heavily incentivised to make AMD miner, since they are the vast majority, cheaper hardware, better OpenCL programming (Nvidia users insist on CUDA ports, because Nvidia refuses to properly support OpenCL). Nvidia doesn't support OpenCL 1 very well, and OpenCL 2 support is nowhere in sight, even though AMD cards from 4 years ago support it. So blame Nvidia for trying to make everything proprietary, and laughing at any open effort. In a better world, Nvidia miners wouldn't need dedicated CUDA ports to run fast. Nvidia mocks anything being open, AMD whole hardheartedly embraces it, so it is odd you want more FOSS effort from products of the company that despises it..... Even so, with an optimized 1070 CUDA kernel, 480 is going to be better cost/perf, so you aren't really helping out miners that much. Current SA is far from perfect optimization, but 470 still beats 1070, because EquiHash is heavily memory limited, just like Ethereum (which has optimized Nvidia miners).